Multiple myeloma (“MM”) represents a malignant proliferation of plasma cells derived from a single clone. The terms multiple myeloma and myeloma are used interchangeably to refer to the same condition. The myeloma tumor, its products, and the host response to it result in a number of organ dysfunctions and symptoms of bone pain or fracture, renal failure, susceptibility to infection, anemia, hypocalcemia, and occasionally clotting abnormalities, neurologic symptoms and vascular manifestations of hyperviscosity. See D. Longo, in Harrison's Principles of Internal Medicine 14th Edition, p. 713 (McGraw-Hill, New York, 1998). No effective long-term treatment currently exists for MM. It is a malignant disease of plasma cells, manifested as hyperproteinemia, anemia, renal dysfunction, bone lesions, and immunodeficiency. MM is difficult to diagnose early because there may be no symptoms in the early stage. The disease has a progressive course with a median duration of survival of six months when no treatment is given. Systemic chemotherapy is the main treatment, and the current median of survival with chemotherapy is about three years, however fewer than 5% live longer than 10 years (See Anderson, K. et al., Annual Meeting Report 1999. Recent Advances in the Biology and Treatment of Multiple Myeloma (1999)).
While multiple myeloma is considered to be a drug-sensitive disease, almost all patients who initially respond to chemotherapy eventually relapse (See Anderson, K. et al., Annual Meeting Report 1999. Recent Advances in the Biology and Treatment of Multiple Myeloma (1999)). Since the introduction of melphalan and prednisone therapy for MM, numerous multi-drug chemotherapies including Vinca alkaloid, anthracycline, and nitrosourea-based treatments have been tested (See Case, D C et al., (1977) Am. J. Med 63:897 903); however, there has been little improvement in outcome over the past three decades (See Case, D C et al., (1977) Am. J. Med 63:897 903; Otsuki, T. et al, (2000) Cancer Res. 60:1). New methods of treatment, such as combination therapies utilizing monoclonal antibodies, therapeutic agents, and small molecule inhibitors of cellular receptors and/or proteins implicated in MM, are needed.